1. Field of the Invention
The present invention relates to electric power connectors and more specifically, to a female connector terminal, which has a tapered tubular contact portion for receiving a rod-like metal contact of a male connector terminal positively, and a clamping shell clamped on the tapered tubular contact portion to enhance contact connection between the tubular contact portion and the rod-like metal contact of the inserted male connector terminal.
2. Description of the Related Art
Following fast development of computer technology, the fabrication or application of many modern products has a great concern with electronic technology. Electronic technology has also been intensively employed to improve the quality of products. Therefore, many electronic technology-related products are commonly seen in our surroundings. The application of modern technology not only improves the quality of products but also gives added functions to the products. Therefore, regular electronic products are commonly equipped with many electric connectors, such as power connector, A/V connector, USB connector, RJ connector, memory connector, etc. for the connection of a variety of peripheral apparatus.
FIG. 8 illustrates an electric power connector set according to the prior art. According to this design, the electric power connector set is a first (male) connector A and a second (female) connector B. The first (male) connector A comprises an electrically insulative shell A1, and a male metal contact A2 mounted in the electrically insulative shell A1. The male metal contact A2 has a front extension plug portion A21. The second (female) connector B comprises an electrically insulative shell B1, and a female metal contact B2 mounted in the electrically insulative shell B1. The female metal contact B2 has a front tubular receiving portion B21 for receiving the front extension plug portion A21 of the male metal contact A2 of the first (male) connector A. This design of electric power connector set is still not satisfactory in function. Because the male metal contact A2 and the female metal contact B2 have a varied diameter along their length, frequently plugging the front extension plug portion A21 of the male metal contact A2 of the first (male) connector A into the front tubular receiving portion B21 of the female metal contact B2 of the second (female) connector B and removing the first (male) connector A from the second (female) connector B tend to cause stress concentration at the contact area, causing the metal contact A2 or B2 to be biased or deformed. Inserting the deformed first (male) connector A into the second (female) connector B with force will cause the second (female) connector B to split or to break, resulting in a connection failure.
In order to eliminate the aforesaid problem, another electric power connector set is developed, as shown in FIG. 9. According to this design, the electric power connector set comprises a first (male) connector terminal E and a second (female) connector terminal C for receiving the first (male) connector terminal E. The first (male) connector terminal E has a forwardly extending rod-like metal contact E1. The second (female) connector terminal C has a forwardly extending contact hole Cl for receiving the rod-like metal contact E1 of the first (male) connector terminal E, a recessed portion C2 extending around the periphery corresponding to the contact hole C1, and an elongated slot C3 cut through the periphery in communication between the contact hole C1 and the recessed portion C2. Further, a C-shaped clamping plate D is fitted into the recessed portion C2 and clamped on the periphery of the second (female) connector C. The contact hole C1 of the second (female) connector C has a diameter slightly greater than the rod-like metal contact E1 of the first (male) connector terminal E. After insertion of the rod-like metal contact E1 of the first (male) connector terminal E into the second (female) connector terminal C, the rod-like metal contact E1 cannot be kept in positive contact with the contact hole C1, and therefore the C-shaped clamping plate D is necessary to impart a compression force, forcing the contact hole C1 into contact with the rod-like metal contact E1 of the first (male) connector terminal E. However, because the C-shaped clamping plate D is smoothly arched, the smoothly arched inner surface does not give much friction force to the periphery of the second (female) connector terminal C. When inserting the rod-like metal contact E1 of the first (male) connector terminal E into the contact hole C1 of the second (female) connector terminal C, the C-shaped clamping plate D may rotate relative to the periphery of the second (female) connector terminal C. If an opening D1 between the two opposite side edges of the C-shaped clamping plate D is in alignment with the elongated slot C3, the C-shaped clamping plate D will be forced to extend outwards and to deform upon insertion of the rod-like metal contact E1 of the first (male) connector terminal E into the contact hole C1 of the second (female) connector terminal C, lowering the clamping force. When the clamping force of the C-shaped clamping plate D is reduced to a certain extent, the contact between the rod-like metal contact E1 of the first (male) connector terminal E and the contact hole C1 of the second (female) connector terminal C becomes unstable.
Therefore, it is desirable to provide an electric power connector set that eliminates the drawbacks of the aforesaid prior art designs.